1. Field of the Invention
The present invention relates to a three-dimensional graphics system capable of three-dimensional graphics color display.
2. Description of the Background Art
A conventional three-dimensional graphics system has a geometric operation portion, a drawing operation portion, a drawing executing portion, and a drawing unit. The geometric operation portion performs geometric operations to obtain geometrically-processed three-dimensional data; for example, on the basis of three-dimensional object data defining three-dimensional objects arranged on a virtual three-dimensional space, the geometric operation portion computes, for each frame, two-dimensionally projected coordinates of the objects defined by the three-dimensional object data, as seen from a certain visual point.
The drawing operation portion performs drawing operations on the basis of the geometrically-processed three-dimensional data and provides three-dimensional graphic drawing data which is defined in pixels on a two-dimensional space assigned in a frame memory.
The drawing unit provides three-dimensional graphics display on a two-dimensional display screen in a display unit on the basis of the three-dimensional graphics drawing data.
The three-dimensional object data, the geometrically-processed three-dimensional data and the three-dimensional graphic drawing data each include three-dimensional coordinate data (X, Y, Z), xcex1 value (data which indicates transmittance), color data (R, G, B), and texture coordinate data (U, V) for each vertex forming three-dimensional objects.
Accordingly, even when changing only the color of an object, the geometric operation portion and the drawing operation portion must compute on the basis of three-dimensional object data defining the changed color data, which unnecessarily consumes the processing time.
According to a first aspect of the present invention, a three-dimensional graphics system comprises: color data transforming means receiving three-dimensional data defining a three-dimensional object and having original color data with a predetermined number of bits, for transforming the original color data into reduced color data composed of a smaller number of bits than the predetermined number of bits to generate three-dimensional data for operation; and processing means for applying processing including color processing operation based on the reduced color data to the three-dimensional data for operation to generate graphics drawing data corresponding to the three-dimensional object.
Preferably, according to a second aspect of the invention, in the three-dimensional graphics system, the processing means comprises color information storage means containing a plurality of pieces of display color information in a one-to-one correspondence with a plurality of color specifications definable with at least part of the reduced color data, and the processing means reads from the color information storage means the display color information corresponding to the color specifications defined by at least part of the reduced color data on the basis of the reduced color data and performs the color processing operation.
Preferably, according to a third aspect of the invention, in the three-dimensional graphics system, at least part of the plurality of pieces of display color information stored in the color information storage means can be changed in its contents.
Preferably, according to a fourth aspect of the invention, in the three-dimensional graphics system, the three-dimensional data further comprises display color selecting information and the three-dimensional data for operation further comprises the display color selecting information. The plurality of pieces of display color information comprise a first number of pieces of first display color information in a one-to-one correspondence with a first number of first color specifications which can be defined with a first number of bits in the reduced color data and a second number of pieces of second display color information in a one-to-one correspondence with a second number of second color specifications which can be defined with a second number of bits in the reduced color data, and the color information storage means comprises first color information storage means containing the first number of pieces of first display color information and second color information storage means containing the second number of pieces of second display color information. The color processing operation performed by the processing means comprises a first color processing operation performed by reading from the first color information storage means the first display color information corresponding to the first color specifications defined by the first number of bits in the reduced color data, and a second color processing operation performed by reading from the second color information storage means the second display color information corresponding to the second color specifications defined by the second number of bits in the reduced color data. The processing means performs one of the first and second color processing operations on the basis of the color specification selecting information in the three-dimensional data for operation, and the second number of pieces of second display color information stored in the second color information storage means can be changed in its contents.
Preferably, according to a fifth aspect of the invention, in the three-dimensional graphics system, the first number of pieces of first display color information stored in the first color information storage means cannot be changed.
Preferably, according to a sixth aspect of the invention, in the three-dimensional graphics system, the display color information comprises information equivalent in amount to the information in the original color data.
According to a seventh aspect of the invention, a three-dimensional graphics system comprises: color data transforming means receiving three-dimensional data defining a three-dimensional object and having original color data with a predetermined number of bits, for transforming the original color data into color data for operation to generate three-dimensional data for operation; and processing means for applying processing including a color processing operation based on the color data for operation to the three-dimensional data for operation to generate graphics drawing data corresponding to the three-dimensional object, the processing means comprising color information storage means containing a plurality of pieces of display color information in a one-to-one correspondence with a plurality of color specifications which can be defined with at least part of the color data for operation, the processing means reading from the color information storage means the display color information corresponding to the color specifications defined by at least part of the color data for operation and performing a first color processing operation, the color processing operation including the first color processing operation, wherein the plurality of pieces of display color information stored in the color information storage means can be changed in its contents.
Preferably, according to an eighth aspect of the invention, in the three-dimensional graphics system, the three-dimensional data further comprises display color selecting information, the three-dimensional data for operation further comprises the display color selecting information, and the color data for operation comprises the original color data itself. The processing means performs, as the color processing operation, one of the first color processing operation and a second color processing operation based on all information in the color data for operation, on the basis of the display color selecting information in the three-dimensional data for operation.
According to the three-dimensional graphics system of the first aspect of the invention, the processing means uses the reduced color data having a fewer bits than the predetermined number of bits as color data corresponding to the original color data, so that the operation time consumed by the processing means can be reduced by the reduction in bit number of the color data.
According to the three-dimensional graphics system of the second aspect, the processing means appropriately reads from the color information storage means the display color information corresponding to the reduced color data by using the reduced color data as the index data. The processing means can thus smoothly perform the color processing operation on the basis of the reduced color data with a smaller number of bits than the predetermined number of bits in the original color data.
According to the three-dimensional graphics system of the third aspect, the contents of at least part of the pieces of display color information stored in the color information storage means can be changed from outside, so that the contents of the color display provided by the display means which display three-dimensional graphics in color on a two-dimensional screen on the basis of the graphics drawing data, can be changed by changing the contents of the display color information corresponding to the color specifications defined by at least part of the reduced color data, without the need to change the contents of the reduced color data.
As a result, when re-displaying the same three-dimensional object in different coloring, the colors can be changed just by changing the contents of the display color information, without changing the three-dimensional data and the three-dimensional data for operation, which allows the processing means to perform the operation at high speed without overhead at all, thus remarkably improving the processing performance of the entire three-dimensional graphics system.
According to the three-dimensional graphics system of the fourth aspect, the contents of the second number of pieces of second display color information stored in the second color information storage means can be changed from outside. Accordingly, when the processing means performs the second color processing operation, the contents of the color display can be changed by changing the contents of the second display color information corresponding to the color specifications defined by the second number of bits in the reduced color data, without changing the contents of the reduced color data.
According to the three-dimensional graphics system of the fifth aspect of the invention, the contents of the first number of pieces of first display color information stored in the first color information storage means cannot be changed from outside. Hence, when the processing means performs the first color processing operation, stable color display can be presented by always using the same kinds of colors.
According to the three-dimensional graphics system of the sixth aspect of the invention, the amount of the display color information is equivalent to that of the original color data, so that the display color information can represent colors equivalent to the colors represented by the original color data.
According to the three-dimensional graphics system of the seventh aspect of the invention, the contents of the pieces of display color information stored in the color information storage means can be changed from outside. Accordingly, when the processing means performs the first color processing operation, the contents of the color display can be changed by changing the contents of the display color information corresponding to the color specifications defined by at least part of the color data for operating, without changing the contents of the color data for operating.
As a result, when re-displaying the same three-dimensional object in different coloring, the colors can be changed without changing the three-dimensional data and the graphics drawing data at all, which allows the processing means to perform the operation at high speed without overhead at all, thus significantly improving the processing performance of the entire three-dimensional graphics system.
According to the three-dimensional graphics system of the eighth aspect of the invention, the processing means performs one of the first color processing operation and the second color processing operation based on all information in the color data for operation, on the basis of the display color selecting information in the three-dimensional data for operation.
As a result, since the color data for operation is the original color data itself, all kinds of colors that the original color data can represent can be used in color display when the processing means performs the second color processing operation.
The present invention has been made to solve the problem above, and an object of the present invention is to provide a three-dimensional graphics system capable of color display with reduced operation time.
These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.